Fuel-injection device for internal-combustion engines



March 20, 1928.

E. VON SALIS FUEL INJECTION DEVICE FOR INTERNAL COMBUSTION ENGINES Filed Nov. 4. 1924 lator whose spring has also a valve-seating,

Patented Mar. 20, 1928.

UNITED STATES PATENT OFFICE.

EDUARD VON SALIS, OF WINTERTHUR, SWITZERLAND, ASSIGNOR TO BUSCH-SULZER BROS-DIESEL ENGINE COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OP MISSOURI.

FUEL-INJECTION DEVICE FOR INTERNAL-COMBUSTION ENGINES.

Application led November 4, 1924, Serial No.v 747,706, and in Germany November 28, 1923.

The invention relates to so-called airless injection engines and its object is toprovide a simple means of injecting the fuel into the air previously compressed in the engine cylinder, possessing the several advantages herein below pointed out'or 'made apparent to those skilled in the art.

Referring to the drawing, the single figure is a vertical section through the fuel injectiondevice, a conventional fuel pump being shown on a reduced scale in elevation.

The preferred form of the device, which is the only embodiment of the invention illus trated and which will now be described in detail but without implication of limitation beyond the scope of the invention as set forth in the claims, comprises a fuel-pressure-opened valve, a fuelpressure accumufunction, and a `mechanical control blocking the Valve against opening but periodically releasing it.

The cylinder 1 is provided with :the usual cavity for the reception of the fuel injection device, which is preferably constructed as a unit insertable and removable as such, and having for convenience of assembling and replacement of arts, a divided valve casing 2, 3. The mem ver 2 contains the fuel chamber 4 immediately adjacent the fuel injection opening 5 and served through piping and ducts `6 by the usual pump 7 adapted to give automatically adjustable delivery to suit current engine requirements. The opening .5 is

controlled by the needle valve 8, sprlngclosed and fuel-pressure-opened, whose stem 9 is enclosed by-a fuel pressure accumulator plunger-sleeve 10 slidable with respect to and closely fitting both the stem 9 and a cavity in the member 2 of the valve casing. The' accumulator spring 11 centered by and re-acting between the abutment 12, adjustable by rotation of the bushing 13 screw threaded in the .end of the member 3 of the valve casing, and the thimble 14 threaded to the accumulator plunger-sleeve serves also, alternatively to its accumulator function, and through contact of the inturned end 15 of the thimble 14 with the annular shoulder 16 on the extended valve stem to hold the valve 8 normally seated. A' second spring 17, acting through a bell crank whose upper arm 18Acarries the adjustable wear screw 19 which presses upon the i upper cnd' of the valve stem 9 suffices to seat the valve 8, when the spring 11 is exercising its accumulator function and has no valve-seating effect, and the spring 17 continues to seat the valve except when released by co-action of the cam 20 with the roller` 21 carried by the other arm 22 of the bell crank. The valve 8 in this embodiment of the invention is not mechanically opened but .is-merely blocked by the spring 17, etc, against operation by the pressure of the fuel itself on the shoulder 23 on the valve stem 9 plus the cylinder air pressure on the end of the valve.,

Before the fuel is forced by the pump 7 into the fuel chamber 4 so as to affect the position of the accumulator plunger-sleeve, the parts are in the position shown in the drawings. When the pressure .of the fuel charge increases sufficientlythe accumulator Y plunger 10 is forced upward against the pressure ofthe spring 11 thus freeing the valve 8 from the action of that spring previously exerted through shoulders 15 and 16, but leaving it still subject to the seating action of the spring 17. As the charge displaces the accumulator plun er, it stores'up pressure in the spring 11 w ich, as soon as the cam 20 releases the valve from the blocking action of the spring 17, thus enabling the fuel pressure on the shoulder 23 to open the valve, gives a quick and sharp fuel injection at substantially constant velocity regardless of engine speed, the spring 11 acting as it moves. inward by the shoulders 15 and 16 to close the valve quickly and sharply, the

parts being so related that the spring 17 cannot again act on the valve spindle until the valve has been closed by said action of the spring 11.

It will be noted that while the pressure of the fuel opens the injection valve, such opening does not occur until permitted by the cam 20 and is therefore subject to precise control with relation to the combustion cycle, under all conditions of speed and load. The

valve is'held to its seat by two s rings; both",

of which jointly act on it throng the greater part of the cycle; spring 17 alone acts on it during the process of storing the ,fuel and neither acts on it during the injection period. At the end of the injection period the accumulator spring acts on the valve, to slam it shut and hold it seated until the spring 17 again joins in that function. This terminates the injection very sharply and independently of the cam 20, the spray velocity being practically at its maximum up to the end of the injection. This direct corelation between the discharging fuel and the valve, whereby the latter is certain to close before the accumulator pressure is appreciably diminished constitutes an important feature of this invention in that it also permits a desirable range of selection to be had in reference to the size of the spray orifice and the period Iof the injection together with complete independence of engine speed and injection pressure. Furthermore the preliminary release of the seating pressure, as by the compression by the fuel of the accumulator spring, enables the timing cam to be symmetrical and thus subject to proper action in either direction of rotation. This cam controls only the beginning of the injection.

It is preferred that the fuel chamber be immediately adjacent to the fuel outlet or spray orifice 5 inasmuch as this eliminates pipe friction and produces a better spray, but the term injection opening or fuel injection opening in the claims is not intended to imply that such opening is necessarily the injection nozzle or final outlet to the interior of the engine cylinder.

It'will also be understood that the embodiment of the invention chosen for illustration and described in detail, though preferred, is not exclusive of other embodiments Within the scope of the claims, and it is to be noted in particular that while concentricity of the accumulator spring and valve stem, and the format-ion of the accumulator plunger as a concentric sleeve surrounding the Valvestem is the simplest and most compact arrangment, the parts may be otherwise arranged.

I claim: i

l. An airless fuel injection device for internal combustion engines comprising a fuel injection opening, a valve controlling said opening and having a valve seat surroundmg said opening, means for opening said valve, means blocking said valve against opening, an accumulator having an accumulator spring and a plunger associated therewith and subject to contact with the fuel charge, and means for periodically unblocking the valve, said accumulator being operatively connected to the valve and acting to.

inject fuel when the valve opens and toseat the valve.

2. An airless fuel injection device for internal combustion engines comprising La chamber having a fuel injection opening, a fuel-pressure-opened reciprocating valve closing said opening, means blocking said valvev against opening by fuel. pressure,

means for periodically unblocking said valve and an accumlator plunger sleeve surrounding and fitting the valve stem and fitting and closing the chamber and subject to the pressure of the fuel charge.

3. An airless fuel injection device for internal combustion engines comprising a fuel injection opening, a valve controlling said opening and having a pressure area adapting it to be opened by fuel pressure, means temporarily blocking said valve against opening, an accumulator adapted to store up energy on displacement by fuel when the valve is closed and to inject fuel through said opening when the valve is opened, and operative connections between the accumulator and valve enabling the former to urge the latter toward its seat.

4c. An airless fuel injection device for internal combustion en ines comprising a fuel chamber having a uel injection opening, an accumulator plunger subject to displacement by the fuel, a valve seat surroundingthe opening, and a valve seating on said valve seat controlling said opening and with respect to which when closed said accumulator is movable and which acts as a stop for the accumulator.

5. An airless fuel injection device for internal combustion engines comprising a fuel whamber having a fuel injection opening,-

an accumulator subject to the pressure of the fuel, a valve seat surrounding the opening, a valve seated on said seat controlling said opening, mechanical connections between said accumulator andvalve enabling the accumulator to seat the valve and the valve to act as a stop for the accumulator.

6. An airless fuel injection device for internal combustion engines comprising a fuel injection opening, a fuel chamber in communication therewith, a valve seat surrounding said injection opening, and a valve seating thereon, a fuel pressure accumulator in communication with said chamber comprising an. accumulator spring adapted to seat the valve, a second spring acting on the valve to block the same against opening, and means for periodically nullifying the obstructive effect of said second spring.

7. An airless fuel injection device for internal combustion engines comprising a fuel chamber having an injection opening, a valve seat surrounding said opening, a reciprocating valve normally seated on said seat to close the opening but provided with a pressure area for fuel pressure opening, an accumulator communicating with said chamber, operative connections between the accumulator and the valve to seat the same,

the accumulator including a plunger having and lost motion operative a pressure area inexcess of the said pressure area of the valve, additional means blocking said valve against opening bypfuel pressure,

means for periodically removing said blocking means, and a variable delivery fuel pump for supplying fuel under pressure to the fuel chamber.

8. An airless fuel injection device for internal combustion engines, removable and replaceable as a unit and fitting into a hole through the cylinderl wall and having a cas ing, a fuel chamber therein having a fuel injection opening to the cylinder in the end of the casing, a valve, valve steni and valve seat coaxial with said opening, an accumulator plunger and an accumulator spring both surrounding the valve stem, and operative mechanical connection between the spring and valve.

9. An airless fuel injection device for internal combustion engines mounted directly on the engine cylinder and comprising a fuel injection outlet adapted to spray fuel into said cylinder, a valve seat surrounding said outlet, a valve seating on said seat and having a valve stein, a fuel chamber surrounding said valve immediately adjacent said outlet, a variable delivery fuel pump for delivering charges of fuel to said chamber, means temporarily blocking said valve against opening, and an accumulator plunger sleeve enclosing and fitting the valve stem and subject to displacement by the pressure of fuel entering. sai'd device.

10. In airless fuel injection apparatus for internal combustion engines, a chamber having a fuel injection opening, a valve seat surrounding said opening, a valve seating thereon, an accumulator adapted to be displaced by the fuel and serving on such displacement to store up energy while the valve is closed, means for opening the valve, and operative connections between the accumulator and valve whereby said energy is caused to seat said valve.

11. An airless fuel injection device for internal combustion engines, comprising a valve casing having therein a fuel chamber having-a'fuel injection opening, a valve seat surrounding said opening, a reciprocating valve in the casing seating on said seat, and a fuel pressure accumulator spring supported by and adapted to seat the valve.

12. An airless fuel injection device for internal combustion engines having a valve casing and a fuel injection opening having a valve seat surrounding it, a reciprocating valve seating endwise thereon and closing said opening and havinga stem located axially of said casing and opening and an accumulator ,spring and plunger concentric to the valve within the casing.

13. An airless fuel injection device for internal combustion engines having a casing, a fuel chamber therein having a fuel injection opening, a valve closing said opening, a pump for delivering fuel to said chamber, and. an accumulator spring carried by the valve casing, adapted to store up energy as it is displaced by fuel forced into said chamber by said pump, and lost motion operative connection between the accumulator and the valve.

14. An airless fuel injection device for internal combustion engines comprising a fuel chamber having a fuel injection opening, a valve seat surrounding said opening, a valve seat-ing thereon, means for opening the valve, an accumulator subject to displacement by fuel when the seated valve closes the injection opening thereby storing up energy to inject the fuel charge when the valve is opened, and operative mechanical connections between said accumulator and valve enabling the accumulator to seat the valve.

15. A fuel injection apparatus comprising a vfuel accumulating chamber, resilient means subject to displacement and consequent storing up of energy by the presence or entry of fuel therein prior to injection, a valve commanding the outlet from said chamber to the injection orifice, means whereby the time of closing of said valve is controlled by said resilient means, and means independent of the fuel for controlling Ithe time of opening of said valve.

16. A fuel injection apparatus comprising a fuel accumulating chamber, resilient means subject to displacement by the presence of fuel therein prior to injection, a valve commanding the outlet from said chamber to the injection orifice and closed by the `eX- pansion of said resilient means, and means independent of the fuel for controlling the time of opening of said valve.

17. An 'airless fuel injection device for internal combustion engines comprising a chamber having a fuel injection opening served by the fuel line, a` valve controlling said opening, and two springs loading said valve and one of which is an accumulator spring reacting with fuel in the chamber to store up energy.

18. In an airless fuel injection device, a 'A valve member closing a fuel injection open ing, two springs loading said valve member, one being an accumulator. spring which when acting to accumulate energy releases the valve member from its load, engine driven means for periodically nullifying the load of the other spring when the accumulator is not loading the valve member, and engine driven means for opening the valve when neither spring loads it. I.

19.v In an airless fuel injection device, a Valve member closing a fuel injection opening, two springs initially loading the valve, and means for severally removing their respective loads including engine driven means timed to cause opening of the` valve when thus unloaded.v

20. In an airless fuel injection device, a

fuel accumulating chamber, an outlet valve to said chamber, two springs operatively connected to said valve, mechanically operated means to release the valve'from the action of one of said springs, fuel pressure operated means to release the valve from the action ofthe other spring, and fuel pressure operated means to open the valve on such double release.

21. In a solid fuel injection apparatus, an'injcction valve member, a seat therefor, two springs each acting to seat said injection valve member, means whereby the fuel to be injected is caused to sustain the pressure of one of said springs while the valve is closed and mechanical means for sustaining the pressure of the otherspring when the valve is opened.

22. A fuel injection'apparatus comprising a fuel accumulatng'chamber, an outlet valve for said chamber, means for blocking said valve, resilient means for holding` said valve to its seat, said resilient means being subject to displacement by pressure of fuel in the accumulator chamber to store up energy when the valve is blocked, engine operated means for periodically unblocking the valve, and fuel pressure operated means for openin the valve When unblocked.

In testimony whereof, I have signed this specification.

EDUARD voN SALIS. 

